Implantable medical devices (IMDs) are commonly used to provide treatment to patients. By way of example, implantable medical devices can include cardiac rhythm management devices and neurological stimulation devices, amongst others. Some types of implantable medical devices deliver electrical stimuli to a target tissue, such as in the heart or nervous system, via a lead wire (“lead”) or catheter having one or more electrodes disposed in or about the target tissue. The lead is frequently connected to a pulse generator housing via an assembly commonly referred to as a header. The header serves to provide fixation of the proximal end of the lead and electrically couples the lead with the pulse generator. The pulse generator housing itself is typically hermetically sealed to prevent degradation of the components therein such as control circuitry, batteries, and the like.
Physiological information about a patient can be gathered through the use of implanted sensors. Some implanted sensors use optical techniques to gather information. For example, some implanted oxygen sensors function by shining light into a tissue of the body and then detecting and analyzing the light that is reflected back to determine blood oxygen saturation. In one approach to detecting an analyte optically, light may be generated by a light emitting diode (LED) and then detected using a photodiode. Signals generated by the photodiode representing the detected light are then processed to generate information regarding the physiological state of the patient, such as whether or not they are suffering from hypoxia. This information can then be used in further assessing a patient's condition or can be conveyed to health care professionals via an external unit.
The integration of implanted sensors with implantable medical devices, such as cardiac rhythm management devices and neurological stimulation devices, can offer various advantages. As one example, the information provided by an implanted sensor can be used to aid in the delivery of therapy from an implantable medical device. Specifically, implanted sensor information may reveal a physiological state that suggests altering the manner in which the implantable medical device delivers therapy.
However, the integration of implanted sensors with implantable medical devices also poses various challenges. For example, in the context of implanted optical sensors, one challenge is coupling both optical signals and electrical signals between leads and pulse generators in an efficient design. Accordingly, there is a need for systems and methods of efficiently integrating optical signals with implanted medical devices.